Fancy fingers
Have you ever seen a clock like the one in the picture below?
The marks on the face of this clock are called Roman numerals. The
Romans were people who lived in Italy long ago. We still use their
numerals to mark the hours on clocks, for dates on buildings, and other
special things.
The Romans seemed to like straight lines, so they made their numerals
very straight and stiff. They are also rather fancy, with little
crosslines at the top and bottom. But even so, the Roman numerals of
2,500 years ago are really nothing but pictures of fingers. The Roman
word for
j nr* iin [a/]{.smallcaps}
finger was digitus, from w^7^hich we get our word digit
[(dihj]{.smallcaps} iht). And digit means “finger,” as well as any
numeral from 0 to 9.
As you can see, the numerals for one, two, three, and four are just like
fingers held straight up. The numeral for five looks something like an
open hand with the fingers held together, away from the thumb. And the
numeral for ten looks a bit like two crossed hands.
In ancient times, Roman numerals could be written in any order because
each numeral ahvazjs stood for the same number. But as a rule, the
largest numeral was written first.
Much, much later, the idea of subtraction was introduced, mainly to save
space. When the first numeral is smaller than the second, it is
subtracted from the second numeral. Thus IV means to subtract I from V
(1 from 5), or 4.
If you look closely at the picture of the clock face, you will see that
it has the early Roman numeral IIII and the later Roman numeral IX. For
some reason, clockmakers almost always show these two numerals this way.
For most other numbers, the Romans made combinations of the first ten
numerals. Twelve was a ten and two ones, XII. Fifteen was a ten and a
five, XV. Twenty was two tens, XX.
Letters were used as symbols for the large numbers. The Romans used L
for fifty, C for one hundred, D for five hundred, and M for one
thousand.
Can you write 1,528 in Roman numerals?